This project is devoted to increasing our understanding of the basic biology of mammalian ciliated respiratory epithelial cells. Primary emphasis will be on the effects of infectious and noninfectious agents on ciliated cell motion, metabolism, and morphology. Model systems will include hamster trachea organ (explant) cultures vitro and will be permitted to interact with agents known to induce ciliostasis and/or cytonecrosis (for example: Mycoplasma pneumoniae; toxic gases such as sulfur dioxide and nitrogen dioxide; and heavy metals such as cadmium, nickel, and chromium). Treatments will be both individual and combined, in order to detect synergistic reactions. Assays will include an electronic, quantitative assessment of the ciliary beat frequency; cellular ATP content, dehydrogenase activity, and respiration; and both gross and fine structure as revealed by light and electron (scanning and transmission) microscopy. This analysis of normal cytopathic ciliated respiratory cells will be developed into an accurate characterization of the stucture and function for this unique cell type.